public async Task AddShow(Guid cinemaId, Guid showId, CreateShowRequest request)
{
Cinema cinema = await _ctx.Cinemas.Include(c => c.Shows).FirstOrDefaultAsync(c => c.Id == cinemaId);
Movie movie = await _ctx.Movies.FindAsync(request.MovieId);
Dictionary <Ticket, decimal> priceList = request.PriceList.ToDictionary(x => x.Kind, x => x.Price);
Show show = ShowFactory.Create(showId, cinema, movie, request.Date, priceList);
cinema.AddShow(show);
await _ctx.SaveChangesAsync();
}